EVAPORATION APPARATUS, VAPOR DEPOSITION APPARATUS, AND EVAPORATION METHOD
An evaporation apparatus ( 100 ) is described, particularly for evaporating a reactive material such as lithium. The evaporation apparatus ( 100 ) includes an evaporation crucible ( 110 ) for evaporating a liquid material ( 105 ), a material conduit ( 120 ) for supplying the liquid material ( 105 ) to the evaporation crucible ( 110 ), and a valve ( 150 ) configured to close the material conduit ( 120 ) by solidifying a part of the liquid material ( 105 ) in the material conduit ( 120 ) with a cooling device ( 152 ). The valve ( 150 ) may include a cooling gas supply ( 154 ) for a cooling gas ( 106 ), and the cooling device ( 152 ) may be configured to cool the liquid material ( 105 ) with the cooling gas ( 106 ). Further described are a vapor deposition apparatus ( 200 ) for coating a substrate as well as an evaporation method.
1 . An evaporation apparatus, comprising:
an evaporation crucible for evaporating a liquid material;
a material conduit for supplying the liquid material into the evaporation crucible; and
a valve configured to close the material conduit by solidifying a part of the liquid material in the material conduit with a cooling device.
2 . The evaporation apparatus according to claim 1 , wherein the valve further comprises a cooling gas supply for guiding a cooling gas to the cooling device, the cooling device configured to cool the liquid material with the cooling gas.
3 . The evaporation apparatus according to claim 2 , wherein the cooling gas supply is a noble gas supply, particularly an argon supply.
4 . The evaporation apparatus according to claim 2 , wherein the cooling gas supply is configured to guide the cooling gas through a cooling passage of the cooling device with at least one or more of: (i) a gas pressure in a range from 2 bar to 20 bar, (ii) a gas velocity in a range from 15 m/s to 50 m/s, and (iii) a mass flow in a range from 10 slm to 50 slm.
5 . The evaporation apparatus according to claim 1 , wherein the cooling device comprises a cooling passage that surrounds a section of the material conduit and is in thermal contact with the material conduit.
6 . The evaporation apparatus according to claim 5 , wherein the cooling passage extends helically or spirally around the material conduit.
7 . The evaporation apparatus according to claim 1 , wherein a distance between the cooling device and the evaporation crucible is 20 cm or less.
8 . The evaporation apparatus according to claim 1 , further comprising a heatable enclosure or chamber through which the material conduit extends, wherein the cooling device is arranged at the material conduit inside the heatable enclosure or chamber.
9 . The evaporation apparatus according to claim 8 , further comprising a thermal insulation arrangement that at least partially or entirely encloses the cooling device for thermally insulating the cooling device and a section of the material conduit surrounded by the cooling device from a hot environment inside the heatable enclosure or chamber.
10 . The evaporation apparatus according to claim 9 , wherein the thermal insulation arrangement comprises one or more heat shields that coaxially extend around the material conduit.
11 . The evaporation apparatus according to claim 1 , wherein the evaporation crucible is configured to evaporate a reactive material, particularly lithium.
12 . An evaporation apparatus, comprising:
an evaporation crucible;
a material conduit connected to the evaporation crucible; and
a valve configured to close the material conduit by cooling the material conduit with a cooling gas.
13 . A vapor deposition apparatus for coating a substrate, comprising:
the evaporation apparatus according to claim 1 ;
a vapor distributor with a plurality of nozzles for directing material evaporated in the evaporation crucible toward the substrate; and
a movable substrate support for moving the substrate past the vapor distributor.
14 . An evaporation method, comprising:
guiding a liquid material through a material conduit into an evaporation crucible;
evaporating the liquid material in the evaporation crucible; and
closing the material conduit by solidifying a part of the liquid material in the material conduit.
15 . The method according to claim 14 , wherein the part of the liquid material is solidified through cooling with a cooling gas.
16 . The method according to claim 15 , wherein the cooling gas is argon.
17 . The method according to claim 15 , wherein the cooling gas is guided through a cooling passage of a cooling device that surrounds a section of the material conduit.
18 . The method according to claim 17 , wherein the cooling gas in the cooling device has at least one of (i) a temperature of |5° C. or more and |50° C. or less at a position upstream of the cooling passage, (ii) a gas pressure in a range from 2 bar to 20 bar, (iii) a gas velocity in a range from 15 m/s to 50 m/s, and (iv) a mass flow in a range from 10 slm to 50 slm.
19 . The method according to claim 17 , further comprising re-opening the material conduit by stopping a supply of the cooling gas through the cooling passage.
20 . The method according to claim 14 , wherein the liquid material is an alkali metal or an alkaline earth metal.
21 . The method according to claim 14 , further comprising:
guiding evaporated material from the evaporation crucible into a vapor distributor; and
directing the evaporated material from the vapor distributor through a plurality of vapor nozzles toward a substrate for coating the substrate in a vacuum chamber.